1. Field of the Invention
The present invention relates to interposers and electrical testing methods thereof, and, more particularly, to an interposer having a plurality of conductive through holes and an electrical testing method thereof.
2. Description of Related Art
FIG. 1 shows a cross-sectional view of a conventional 3D-IC package structure. Referring to FIG. 1, an interposer 10 having a plurality of copper posts 11 penetrating therethrough is disposed between a semiconductor chip 12 and a packaging substrate 13 to serve as an electrical connection bridge between the semiconductor chip 12 and the packaging substrate 13.
The copper posts 11 are formed by filling a copper material in a plurality of through holes 100 in the interposer 10. However, if the through holes 100 are not completely filled with the copper material, voids or crevices 14 may occur in the copper posts 11. The voids or crevices 14 cannot be inspected visually. Further, since the upper and lower surfaces of the interposer 10 have external conductive elements disposed thereon, a conventional wafer testing method cannot be used to detect the electrical performance of the interposer 10. Therefore, an effective electrical testing method of the interposer 10 is required so as to improve the yield of the 3D-IC package structure.